Medical container stopper

ABSTRACT

A stopper for medical containers such as blood collection tubes having integral flange and plug portions, the flange portion being substantially larger in diameter than the plug portion, which plug portion is sized to sealably close the container. The stopper has opposed wells formed in the flange and plug portions, the well in the flange portion having a relatively flat bottom surface at least as large in diameter as the diameter of the opposed well in the plug portion. The flange portion is constructed to be guided into a tube holder into which it is inserted such that one end of a needle projecting into the interior of the tube holder will penetrate the stopper in the area of the opposed wells so as to avoid otherwise contacting the stopper. The enlarged flange portion also serves to facilitate removal of the stopper from the container without contaminating a handler.

BACKGROUND OF THE INVENTION

This invention relates to stoppers for medical containers and, moreparticularly, to stoppers for blood collection tubes and the like whichenable the use of such collection tubes with oversized tube holders.

The most common sealed fluid sample containers are sealed and evacuatedblood sample collection tubes used for receiving and preserving fortesting samples of fluid blood. When drawing or collecting blood samplessealed and partially evacuated glass collection tubes are frequentlyused with a tube holder sized to receive collection tubes having theirstoppers in place. The tube holder also generally includes a needlecannula extending axially therefrom. In order to permit blood to passinto the collection tube, the stopper is inserted into the tube holderand one end of the double-ended needle or the like punctures and holdsthe stopper and collection tube in place until the desired volume ofblood sample or other substance has been collected. Brush U.S. Pat. No.4,150,666 discloses a blood collection tube holder having asubstantially tubular body open at one end to receive and guide acollection tube as it moves thereinto. The opposite end of the tubularbody is closed by a wall in which a double-ended needle cannula ispositioned. One end of the needle projects outwardly from the end wallof the holder for insertion into a patient's blood vessel while theopposite end of the needle extends axially in the tube holder and ispositioned to penetrate the stopper on the sample tube and establishfluid communication with the interior of the collection or sample tube.With the known constructions, however, it is often necessary to draw anumber of blood samples for different tests from the same patient whilemaintaining the same tube holder needle in the vein of the patient toavoid subjecting the patient to multiple punctures. Recently the use ofrelatively small blood collection tubes, such as 10 millimeter tubeswhich accommodate samples of two to four milliliters in volume, has beenpreferred and has become common practice due to the small sample sizesrequired for many of the blood tests most frequently performed. Othermore extensive blood tests, however, may require larger samples andhence larger volume collection tubes and difficulties can occur if thesame tube holder is used with tubes of widely differing sizes.Furthermore, the technician may find it difficult to maintain a holder,sized for a relatively large collection tube, steady and thedouble-ended needle in the patient's vein while trying to penetrate thecenter portion of a smaller tube stopper with the opposite end of thesame needle. Also, failure to properly align the needle with the centerportion of the small tube stopper can result in occluding or blockingthe end of the double-ended needle in the stopper side wall. Stillfurther, use of relatively small collection tubes with small stoppersapproximating the diameter of the tube makes it difficult for laboratorypersonnel to remove the stopper without getting blood or serum on theirfingers. This can make the handling hazardous especially when samplesmay contain infectious agents, such as hepatitis or AIDS virus.Therefore, it is desired to avoid such difficulties while at the sametime being able to employ a single tube holder for collecting severalblood samples in collection tubes of differing sizes.

The present construction overcomes these and other problems associatedwith the known prior art and includes a tube holder designed to guidethe collection tube and its stopper so that the end portion of theneedle in the holder device will penetrate a central thinner diaphragmportion of the stopper and move through the stopper diaphragm tocommunicate with the interior of the sample tube, thus avoiding thepossibility of moving the open end of the needle against the side wallof the stopper or of the sample tube and blocking or occluding theneedle. The present stopper construction is relatively inexpensive tomake, is easy to use, can be used with containers of differing size andis relatively fail safe.

OBJECT OF THE INVENTION

It is therefore a primary object of the present invention to teach theconstruction and operation of a stopper for medical containers whichavoids the above noted difficulties and shortcomings of the known priorart devices.

Another object is to provide a stopper that lends itself to use inrelatively small size blood collection tubes and also enables such smallcollection tubes to be used with tube holders sized for use with largercollection tubes.

Another object is to provide a stopper for use with relatively smallcollection tubes which decreases the possibility of occluding orblocking the flow path through an open ended needle that is provided topenetrate the stopper.

A further object is to provide a stopper for blood collection tubes andlike containers which can be relatively easily removed therefrom.

Another object is to teach the construction and operation of arelatively inexpensive, easy to use stopper for use on devices such asblood collection tubes and the like.

Another object is to provide a versatile stopper that facilitatesobtaining one or more blood samples from a patient while subjecting thepatient to minimal discomfort and body punctures.

Another object is to make it easier and more reliable to take bloodsamples from patients.

A still further object is to provide a stopper for collection tubes suchas blood sample collection tubes which reduces the possibility of theuser coming in contact with the contents thereof.

These as well as other objects and advantages of the present inventionwill become apparent to those skilled in the art from the followingdetailed description and accompanying drawing of a preferred embodiment,wherein:

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a cross-sectional view through the center of a stopperconstructed in accordance with the teachings of the present invention;

FIG. 2 is a bottom view of the stopper as shown in FIG. 1;

FIG. 3 is a top view of the stopper shown shown in FIG. 1;

FIG. 4 is a side view showing the stopper of FIG. 1 mounted in the openend of a collection tube; and

FIG. 5 is an enlarged cross-sectional view showing the stopper-tubeassembly of FIG. 4 inserted into a tube holder having a needle mountedthereon in position such that the stopper will be pierced and penetratedby one end of the needle.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawing more particularly by reference numbers, FIG. 1shows a stopper 10 constructed according to the present invention. Thestopper 10 is shown as being of unitary construction having an annularflange portion 12 and a smaller diameter tube-closing plug portion 14.The flange portion 12 has an end face 16 which includes a centrallylocated depression or well 18 defined by tapered side and bottomsurfaces 20 and 22 respectively. The flange 12 also has a frusto-conicalouter surface 24 which extends from the end face 16 to its opposite endwhere it meets the outer periphery of radial face 26. The flange portion12 is larger in diameter than the plug portion 14 by a substantialfactor typically by a factor of from about 1.4 to about 2.0 times. Apreferred ratio of these diameters is about 1.7. This preferred ratioenables a standard 10 millimeter collection tube to be used with astandard needle holder device having an inside diameter of from about0.665 inch to 0.720 inch. At the juncture of flange and plug portions 12and 14 an annular inwardly extending groove 28 is formed which enablesthe portions 12 and 14 to move angularly relative to each other to someextent thereby facilitating inserting and removing the plug portion 14into a container or collection tube as will be described.

The plug portion 14 is formed by an annular wall 30 which has an outersurface 32 that preferably has a slight end-to-end taper as shown toenable the plug portion 14 to be relatively easily and sealably insertedinto the open end 34 of a container 36 such as the container shown inFIGS. 4 and 5. The stopper 10 is preferably constructed of a relativelyresilient material such as rubber or rubber like composition includingthermoset rubbers such as butyl rubber, bromobutyl rubber, styrenebutadiene rubber, nitrile butadiene rubber as well as thermoplasticrubbers such as polyester elastomer, styrene-base elastomer,polybutadiene or polyolyfin elastomer so that there is some give andcompression of the plug portion 14 as it is inserted. Any of thecommonly used lubricating agents and mold release agents are suitablefor use with the particular rubber composition selected to be used.Also, additives can be employed in the stopper such as dyes, pigments,hemorepellants, and the like. It is also contemplated to have the freeend of the plug portion 14 formed with an optional reduced diametergroove 37 to facilitate inserting the plug portion 14 into open end 34of the container 36.

The plug portion 14 is annular in shape and has an inside surface 38which terminates in a bottom or end surface 40 as clearly shown inFIG. 1. The bottom or end surface 40 is spaced from the bottom surface22 of recess or well 18 formed in the end surface of the flange portion12, and it is preferred that the surface 22 which forms the bottom ofthe well 18 be at least as large in area, and preferably somewhatlarger, than the area of the bottom surface 40 of recess 44 in the plugportion 14. The portion 46 of the stopper 10 between the surfaces 22 and40 can be referred to as the diaphragm portion of the stopper 10, and isthe portion through which a needle or other piercing instrument projectswhen the device is to be used to receive a blood or other sample duringoperation of the device as will be described more fully hereinafter.

In FIG. 4, the stopper 10 is shown mounted in the open end 34 of thetubular container 36 which container may be a small sample container ortest tube. The container 36 has a side wall 48 which is shown as tubularin shape terminating in a closed end wall 50. The inner surface 52 ofthe container 36 is sized to slidably and sealably receive the plugportion 14 of the stopper 10 when the stopper is pressed or twistedtherein. The stopper 10 is usually pressed into the open end 34 of thecontainer 36 until the end 54 of the container bears against the surface26 on the flange portion 12 of the stopper. Insertion of the plugportion 14 into the container can take place during manufacture in whichcase the stopper and the container including especially the interior ofthe container are sterilized and may be partially evacuated leaving avacuum condition therein. Furthermore, the stopper 10 should not be sotight-fitting in the container 36 as to be difficult to remove since thestopper may be required to be removed by a technician or other person inorder to extract the blood or other sample contained therein for somepurpose, although it is also contemplated to remove the sample by meansof another needle on an extraction device. Removal of the stopper 10from the container 36 is facilitated by having the flange portion 12relatively large in diameter for ease of grasping and twisting. Byhaving the flange portion relatively large and easy to grasp iteffectively isolates the open end 34 of the container 36 from thefingers of the remover. Also, the larger flange portion makes it lesslikely that the person removing the stopper will lose control and spillthe contents including spilling the contents onto his or her skin orclothing.

The subject stopper, and the container in which it is installed, aredesigned to be used in association with a holder device such as theholder device 56 as shown in FIG. 5. The holder device 56 is shownincluding an elongated tubular portion 58 closed at one end by wall 60and having an outwardly extending flange portion 62 at the opposite end.The closed end wall 60 has a central portion 64 which supports a doubleended needle member 66 which is shown having a portion 68 extendinginside the holder 56 and a portion 70 extending from the end of theholder. Both ends 72 and 74 of the needle 66 are open and both aretapered as shown to facilitate their penetration into the stopper orinto skin of a patient with which they come in contact.

The tubular portion 58 of the holder 56 has a cylindrical inner surface76 which is sized to slidably receive the tapered flanged portion 12 ofthe stopper 10 when the stopper and the container on which it isinstalled are inserted into the holder 56 as shown in FIG. 5. Ideallythe container 36 and the holder 56 should be in axial alignment when thecontainer is inserted but this may not always be the case especiallywhen the insertion is made while the end portion 70 of the needle 66 isinserted into the vein of a patient from whom a blood sample is beingremoved. It is important to the operation of the present device however,that whether the members 36 and 56 are in precise axial alignment or notthat the inner end portion 68 of the needle 66 engage and pierce thediaphragm portion 46 of the stopper 10 and in so doing will passtherethrough and enter the container 36 somewhere in the region definedwithin the cavity or plug well portion 44 . In other words, regardlessof the angle at which the needle portion 68 engages and pierces thestopper 10 it should not be possible for the needle to pierce thestopper so as to penetrate the annular portion 30 of the plug portion14. This assures that the piercing end 72 of the needle 66 will never beblocked or occluded when a blood sample is being taken from the vein orartery of a patient. This is especially important when using smalldiameter collection tubes since the likelihood of blocking or occludingthe end 72 of needle 66 increases substantially when relatively smallcollection containers or tubes are used with correspondingly smallstoppers, such, for example, as 10 millimeter blood collection tubes inholders that are constructed to accomodate larger collection tubes suchas 16 millimeter collection tubes.

In a typical application a single holder device 56 is therefore able toreceive different size collection tubes even while the opposite endportion 70 of the needle 66 remains inserted into a patient's vein. Thismeans that once the needle has been inserted into a vein the containersinto which the blood being drained is collected can be changed in orderto allow the blood to flow into several different containers from thepatient. Furthermore, changing from one size container to another can beaccomplished with minimal blood loss and with minimal possibility thatthe blood being taken will come into contact with the technician,doctor, or nurse performing the procedure. These are importantconsiderations and mean that blood samples of different sizes can betaken from the same patient without having to reinsert the needle intothe patient for each sample and without causing the patient additionaldiscomfort. The construction of the present stopper also protectsagainst the one taking the samples piercing the stopper in a mannerwhich will obstruct the blood flow, and this is true regardless of theangle at which the container is inserted into the holder device. All ofthese are important features and advantages and ones which are availablewhen using the present construction.

In a typical situation it has been found that the outside diameter atthe widest point on the flange 12 should be between about 1.4 and about2.0 times the diameter of the plug portion 14 at its widest point, andthe surface 22 should be substantially larger than the surface 40, andshould be such as to assure that the needle will be properly located topenetrate the stopper regardless of the various possible angles of thecontainer 36 when inserted into the holder 56. In the case of a typical10 millimeter blood collection tube having an inside diameter of about9.85 millimeters, the outside diameter of the flange portion 12 shouldbe in the range from about 1.6 to about 1.8 times the inside diameter ofthe collection tube 36, i.e. from about 15.8 to about 18.0 millimeters,and preferably between about 16.8 to 17.8 millimeters. Such dimensionsassure proper guidance and alignment of the collection tube 36 fittedwith such a stopper 10 and the successful penetration of the needleportion 68 into and through the diaphram portion 46 of the stopper. Itshould also be noted that as the diameter of the collection tube becomessmaller in relation to the diameter of the holder 56 there is a greaterchance for trouble when using the device. This is especially true wheninserting a 10 millimeter collection tube into a standard holder whichhas an inside diameter of about 0.720 inch at the open end thereof.

Not only is the alignment of the needle an important consideration,particularly when using relatively small diameter containers andstoppers, but if the point at which the needle 66 initially penetratesis in a sloping wall portion of the stopper as for example in wallportion 20, it may develop what is known as "point roll" which is acondition that tends to deflect the needle sidewardly and outwardlytoward the side wall 30 of the plug portion 14. If a relativelythin-walled needle of small guage is used, "point rolling" may deflectan originally straight needle to such an extent that the free endthereof engages the wall 30 and is blocked or becomes occluded or movesinto the side wall 30 of the plug portion 14. Any of these conditionscan produce a "no vacuum" effect and prevent or at least discouragemovement of the blood from the patient into the collection tube 36. Sucha condition may also require that the container 36 be withdrawn from theholder so that the needle will be withdrawn to enable anotherpenetration to take place before the device will operate properly. Thepossibility of "point roll" is further obviated in the presentconstruction by having the bottom wall portion 22 of the outer recess orwell 18 made relatively large and flat so that the needle will not be aslikely to attempt to enter at a sloping wall portion of the stopper.Consequently, the "point roll" condition is largely overcome by theconstruction of the present stopper.

It should also be kept in mind that with the present construction theamount of possible angular movement between the stopper 10 and theholder member 56 into which it is positioned is limited by the size andshape of the collection tube 36 and to some extent by the length of thecollection tube. The important thing is that the varied possible angularpositioning of the stopper be such that the needle will never be able toenter the stopper so as to produce the undesirable conditions set forthabove.

Thus there has been shown and described a novel stopper construction foruse with medical containers, and especially with blood collection tubesand the like which fulfills all of the objects and advantages soughttherefor. It will be apparent to those skilled in that art, however,that many changes, modifications, variations, and other uses andapplications for the subject stoppers are possible and contemplated. Allsuch changes, modifications, variations, and other uses and applicationswhich do not depart from the spirit and scope of the invention aredeemed to be covered by the invention which is limited only by theclaims which follow.

What is claimed is:
 1. In combination, a tube having an opening, astopper for closing the opening in said tube, and a holder for said tubeand stopper, comprising:a holder body closed at one end and open at anopposite end with an axially extending hollow needle positioned thereinsuch that one end of said needle extends into said holder body towardsaid opening and an opposite end of said needle extends outside saidholder body, a hollow elongated blood collection tube having a tubularside wall portion terminating at one end of said tube in a closed endwall portion and having a round in diameter open end opposite the closedend wall portion of said tube, a stopper body having round and connectedflange and plug portions, the flange portion of said stopper body beingsubstantially larger in diameter than the plug portion of said stopperbody and sized to be slidably moved into the holder body and against theneedle end extending into said holder body, the largest diameter of theflange portion of said stopper body exceeding the largest diameter ofthe sidewall portion of said tube proximate the opening in said tube bya factor of at least 1.4 and, means forming aligned and opposed cavitiesin the flange and plug portions defining a relatively thin diaphragmportion therebetween.
 2. The tube, stopper and holder combination ofclaim 1 wherein the largest diameter of the flange portion of saidstopper body exceeds the largest diameter of the portion of said tubeproximate the opening in said tube by a factor of from about 1.4 toabout 2.0 times.
 3. The tube stopper and holder combination of claim 1adapted for use on a 10 millimeter tube, wherein the largest diameter ofthe flange portion of said stopper body exceeds the largest diameter ofthe portion of said tube proximate the opening in said tube thereof by afactor of about 1.7 times.
 4. The tube, stopper and holder combinationof claim 1 wherein the diameter of the flange portion of said stopperbody is sufficiently large to prevent misalignment of the diaphragmportion of said stopper body with the axis of said needle when said tubewith said stopper body inserted in the open end of said tube ispositioned stopper first within the open end of said holder body,irrespective of the angle of orientation of said tube with respect tosaid needle.
 5. A medical blood collection kit comprising incombination:a holder body closed at one end and open at an opposite endwith an axially extending hollow needle positioned therein such that oneend of said needle extends into said holder body toward said open endand an opposite end of said needle extends outside said holder body, atleast one small blood collection tube and stopper combination formed bya hollow elongated small diameter tube having a tubular side wallportion terminating at one end of said small tube in a closed end wallportion and having a round in diameter open end opposite the closed endwall portion of said small tube, and a small stopper having connectedflange and plug portions, the flange portion of said small stopper beinglarger in diameter than the plug portion of said small stopper and sizedto be slidably moved into the holder body and against the needle endextending into said holder body, the largest diameter of the flangeportion of said small stopper exceeding the largest diameter of theportion of said small tube proximate the open end in said small tube bya factor of at least 1.4; and at least one large blood collection tubeand stopper combination formed by a hollow elongated large diameter tubehaving a tubular side wall portion terminating at one end of said largetube in a closed end wall portion and having a round in diameter openend opposite the closed end wall portion of said large tube, a largestopper having connected flange and plug portions, the flange portion ofsaid large stopper being substantially larger in diameter than the plugportion and sized to be slidably moved into the holder body and againstthe needle end extending into said holder body, the largest diameter ofthe flange portion of said large stopper exceeding the largest diameterof the portion of said large tube proximate the open end in said largetube by a factor of less than 1.4.
 6. The medical blood collection kitof claim 5 wherein the outside diameter of said small tube of said atleast one small tube and stopper combination is not more than 12millimeters and the outside diameter of said large tube of said at leastone large tube and stopper combination is at least 14 millimeters.
 7. Amethod for collecting blood from an animal body comprising the stepsof:providing a blood collection tube holder in the form of a hollowholder body having an open end, and a needle mounted on said holder bodyopposite the open end of said holder body, with one end of said needleextending into said holder body toward the open end of said holder body,inserting an other end of said needle opposite said one end of saidneedle into a blood vessel of an animal body, communicating blood fromsaid vessel through a bore of said needle to said one end of saidneedle, providing at least one large diameter blood collection tube andat least one smaller diameter blood collection tube, each tube having astopper closure for closing an open end of said respective tube, eachstopper having a plug portion adapted to fit within an open end of eachsaid tube and a flange portion extending out of each said tube, theflange portion of each of said stoppers having approximately the samefunctional diameter corresponding to an inside diameter of said holderbody, and said blood collection tubes having a predetermined outsidediameter such that the diameter of the flange portion of said stopper isat least 1.4 times the outside diameter of the smaller diameter tubesand not more than 1.4 times the outside diameter of the larger diametertubes, positioning one of the larger diameter tubes stopper first intothe open end of said holder body, and advancing said larger diametertube within the holder body until the one end of said needle pierces thestopper of said larger diameter tube, then withdrawing the tube from theholder after a blood sample has collected in the tube, and positioningone of the smaller diameter tubes stopper first into the open end ofsaid holder body, and advancing said small diameter tube within saidholder body until the one end of said needle pierces the stopper of saidsmaller tube, then withdrawing the smaller tube from the holder after ablood sample has collected in the smaller tube.
 8. A method forcollecting blood from an animal body in two different- sized bloodcollection tubes comprising the steps of:providing a hollow collectiontube holder having an open end, a minimum inside holder diameter and adouble ended needle mounted opposite and in alignment with the open endof said holder, providing at least one large blood collection tubehaving an outside large tube diameter slightly smaller than the holderdiameter and closed by a large tube stopper having a flange portion,said flange portion having a diameter at most slightly larger than thetube diameter, providing at least one small blood collection tube havingan outside small tube diameter at most substantially smaller than theholder diameter and closed by a small tube stopper having a flangeportion, said flange portion having a diameter at least substantiallylarger than the small tube diameter, communicating the needle with ablood vessel of an animal body; then using said holder, inserting one ofthe large tubes stopper first into the open end of the holder, pushingthe large tube into the holder until the needle pierces the stopper andblood flows into the large tube, withdrawing the large tube from theholder when a desired sample is collected; and inserting one of thesmall tubes stopper first into the open end of the holder, pushing thesmall tube into the holder until the needle pierces the stopper andblood flows into the small tube, withdrawing the small tube from theholder when a desired sample is collected.